Voltage sag will affect the transient stability of the power system, which may affect the normal operation of the entire grid. For mitigating the voltage sag to protect sensitive loads in a low voltage power system, the Dynamic Voltage Restorer (DVR) based on a power electronic converter with fast response and excellent compensation precision is proposed. It may effectively mitigate serious impacts caused by voltage sag especially in the grid with the solar PV power systems. This paper presents a method of configuration and design of the Perturbation and Observation (P&O) technique for tracking the Maximum Power Point (MPP) of the PV solar system using a string inverter combined with the DVR. The simulation results of the studied on-grid solar PV system are performed in the Simulink toolbox. It can be concluded that the proposed DVR with the hybrid PID and Fuzzy Logic (PID+FL) controller can be applied to enhance the dynamic voltage stability of the studied power system.